Various prior art agricultural implements exist for aerating soil.
FIG. 1 herein shows one example of a prior art soil aeration device 1 which is the subject of U.S. Pat. No. 4,383,580. Such device 1 comprises a frame 14, and uses a pair of rotatable shafts 2,3 each having a longitudinal axis of rotation 30 substantially aligned with that of the other, each mounted perpendicular or substantially perpendicular to the direction of travel ‘A’ of the device. Each shaft 2,3 possesses a plurality of radially outwardly extending tine members 22, which penetrate and cut the soil as the rotatable shafts are moved over the soil.
FIG. 2 shows another example of a prior art device 5 which is the subject of U.S. Pat. No. 4,840,232 assigned to Holland Equipment Ltd. Such device 5 similarly utilizes a frame 14 and a plurality of rotatable shafts 2,3, rotatably mounted thereon, each shaft 2,3 having a plurality of longitudinally spaced radially outwardly extending tine members 22, which penetrate and cut the soil as the rotatable shafts a 2,3 are moved over the soil. Longitudinal axis 30 of the respective rotatable shafts are capable of being adjustably inclined from 70°-90° to the direction of travel of the device by means of a plurality of bolt holes in frame 14 thereof.
Similar devices are disclosed in U.S. Pat. Nos. 5,690,179, 5,823,269, 5,101,910, 4,094,363, and 5,570,846.
U.S. Pat. Nos. 6,691,791 and 7,055,617 each teach a soil aeration apparatus device, having first and second substantially parallel shafts rotatably coupled to a carrier, each shaft having a plurality of soil aerating tines attached thereto, and a gear system to rotate each of the first and second shafts while revolving the first and second shafts about a central axis of the carrier.
Disadvantageously, with increasing use of zero or minimum tillage farming practices in large scale farming, aeration of non-tilled fields having crop residues thereon with aeration devices of the prior art typically results in such units having the tines thereof becoming clogged with residual stalks from previously-harvested crops such as corn, canola, wheat (straw), barley (straw), soybeans, and the like.
Although tillage of such fields with a tillage device such as a disc cultivator (as opposed to an aeration device) is an alternative option to permit working of the crop residues back into the soil, tillage is precisely what is attempted to be avoided with modern day zero-till or minimum till practices, due to the large soil disturbance and resulting difficulty with wind and water erosion of the tilled soil.
Accordingly, a real need exists in the farming industry for aeration devices which are able to leave the soil in a substantially undisturbed form, but yet are able to perform on fields having substantial crop residues thereon without clogging.
A further real need exists in the farming industry for an aeration implement that is able to mulch or cut stalks of crop residues lying on the surface of the soil, to better work them into the soil during aeration so as to thereby improve the aeration of the soil and the fiber content of the soil, both of which increase fertility and crop yield from the soil.